function clickStyleDown(obj){
					var this_id = obj.id;
					debugger
					var el = document.getElementById(this_id);
					el.className = "btn btn_down";
				}
				function clickStyleUp(obj){
					var this_id = obj.id;
					var el = document.getElementById(this_id);
					el.className = "btn";
				}
				function min(){
					var el = document.getElementById("num");
					if(Number(el.value) >= 1){
						el.value = Number(el.value) - 1;
					}
				}
				function add(){
					var el = document.getElementById("num");
					el.value = Number(el.value) + 1;
				}
				function chekNum(){
					var el = document.getElementById("num");
					if(isNaN(el.value)){
						el.value = 0;
					}
				}
				/**
				 * 修改html内容测试，html渲染有效
				 */
				function changeNum(){
					var el = document.getElementById("s1");
					el.innerHTML = "<h1>这个是html的修改效果</h1>"
				}